[Pinky-develop] Union updated

[Peter R. <dr...@us...>]

I've added support for n-way multiple unions to active:Union.  Old tests
pass and I've added a new multi-union test.

Also I added a change.log to the base pinky/ directory so that we can
keep a record of significant updates which will help with tracking
changes between releases.  If you think you've committed a significant
change please record it in the log.

P.

PS Mircea thanks for fixing the typos!  Looking forward to seeing the
Flickr accessor.  We might want to refactor the accessors   package at
some point - but the first decision should be whether we have the URI
logical space right first - that is the significant thing from a users
point of view.  I'm wondering if we should prefix the pinky collection
so we'd have something like

active:Union  -> active:pinkyUnion
active:ForEachEntry -> active:pinkyForEachEntry

The reason for this is that a prefix can be useful to indicate the
interoperability of a tool ecosystem.  See, for example, the
active:sqlXXXX set of accessors or  active:rdfXXXX etc.